Cleaner head assembly for a vacuum cleaner

ABSTRACT

The invention provides a cleaner head assembly for a vacuum cleaner comprising a cleaner head body pivotably attachable to a main body of a vacuum cleaner and a brush housing pivotably mounted on the cleaner head body, the brush housing having a suction opening and a brush bar mounted therein, wherein the brush housing comprises a sealed unit connectable to a vacuum cleaner air inlet via a conduit separate from the cleaner head body. The arrangement allows the brush housing to be doubly articulated with respect to the main body of the vacuum cleaner whilst the suction opening remains in a horizontal plane without requiring the use of seals which must be able to accommodate the articulation of the brush housing.

This application claims priority to International Application No.PCT/GB99/03271 which was published on Apr. 20, 2000.

The present invention relates to a cleaner head assembly for a vacuumcleaner.

BACKGROUND OF THE INVENTION

An upright vacuum cleaner normally comprises a main body containing dirtand dust separating apparatus, a cleaner head rotatably mounted on themain body and having a dirty air inlet, and a motor and fan unit fordrawing dirty air into the dirt and dust separating apparatus via thedirty air inlet so that dirt and dust can be separated from the airflowbefore the clean air is expelled to the atmosphere. The dirty-air inletthrough which dirty air is sucked into the vacuum cleaner is directeddownwardly so that it faces the floor to be cleaned. The dirt and dustseparating apparatus can take the form of a filter bag or, as is known,can alternatively take the form of a cyclonic arrangement. The presentinvention is not concerned with the nature of the dirt and dustseparating apparatus and is therefore applicable to vacuum cleanersutilising either arrangement.

A brush bar is supported in the dirty-air inlet so that it protrudes toa small extent from the inlet. The brush bar is activated mainly whenthe vacuum cleaner is used to clean carpeted surfaces. The brush barcomprises an elongate cylindrical core from which bristles extend alongits length in a radial direction. The brush bar is driven by the motorvia a drive belt so that the brush bar rotates within the inlet.Rotation of the brush bar causes the bristles to sweep along the surfaceof the carpet to be cleaned to loosen dirt and dust and pick up debris.The suction of air causes air to flow around the brush bar andunderneath it to help lift the dirt and dust from the surface to becleaned and then carry it from the dirty-air inlet to the dirt and dustseparating apparatus.

It will be appreciated that the effectiveness of an upright vacuumcleaner will depend upon the amount of dirt and dust which can be pickedup by the cleaner head and passed to the dirt and dust separationapparatus. For each vacuum cleaner there is an optimum configuration forthe relationship between the dirty-air inlet and the carpet to becleaned. Very often, the relationship will be one that maintains thedirty-air inlet in a plane which is parallel to the floor so that themouth of the inlet is horizontal. Ideally then, the dirty air inletshould be maintained completely horizontal to the floor (or at theoptimum angle or configuration) so that the maximum amount of air suckedinto the dirty air inlet travels through the fibres of the carpet beingcleaned before travelling on through the cleaner to the dirt and dustseparating apparatus. However, the angle of inclination of the cleanerhead to the surface may differ when the vacuum cleaner is used ondifferent types of floor surface, eg on carpets with different piles andtextures. Also, the vacuum cleaner is in use moved over the surface tobe cleaned in reciprocating forwards and backwards movements so that thecleaner head travels both forwards and backwards over the surface whilstcollecting dust and dirt via the dirty air inlet. In most cases thecleaner head will be acted upon in different ways by the carpet when itis travelling in different directions and will not maintain good contacton all sides of the dirty air inlet in both directions. Furthermore, theaction of the user can result in the angle of inclination of the handleto the vertical being varied quite significantly during normal use andthis can cause the plane of the dirty air inlet to be lifted, either atthe front or the back, away from the optimum configuration. Any and allof these things can result in a reduction in the effectiveness of thesuction of the cleaner head which can lead to a loss in the maximumlevel of pick-up and then to customer dissatisfaction.

Some attempts have been made to solve this problem by way of manuallyoperated cleaner head lifting and lowering mechanisms by means of whichthe user is able to set the optimum height for the cleaner head when thecleaner is being used on a particular surface. However, these mechanismsonly lift and lower the cleaner head by pivoting about the axis aboutwhich the cleaner head is connected to the main body of the cleaner.They do not address the problem of the dirty air inlet becoming inclinedto the optimum configuration and thereby allowing the inlet suction tobecome less effective. One effective way to address this problem hasbeen described in our copending UK patent application no. 9725777.8which gives full details of a cradle-type arrangement for mounting thebrush bar in the dirty air inlet. The brush bar is mounted in a cradlewhich is itself freely rotatably mounted in the cleaner head. Thedifficulty associated with this arrangement is that the cradle must besealed with respect to the cleaner head and this can be difficult toachieve. The cradle must remain freely rotatable with respect to thecleaner head whilst preventing any loss of suction during use of thevacuum cleaner. The constant movement of the cradle with respect to thecleaner head affects the life of the seal between the cradle and thecleaner head so that the seal can be prone to leakages in a relativelyshort time.

SUMMARY OF THE INVENTION

An object of the present invention is to provide a cleaner head whichmaintains the suction opening of the dirty air inlet in contact with thesurface to be cleaned throughout cleaning. A further object of theinvention is to provide a cleaner head assembly which remains in theoptimum configuration during cleaning. A still further object of theinvention is to provide a cleaner head for a vacuum cleaner which hasimproved pick-up capabilities. A further object is to provide a cleanerhead assembly which requires less maintenance than known assemblies.

The present invention provides a cleaner head assembly as claimed inclaim 1. The invention also provides a vacuum cleaner as claimed inclaim 10. Preferred features are set out in the subsidiary claims.

The cleaner head assembly according to the invention is doublyarticulated with respect to the main body of the vacuum cleaner. Thisallows the brush housing to float freely on the surface to be cleanedeven when the angle of inclination of the handle of the vacuum cleaneris altered during use. The suction opening in the brush housing thusremains essentially in the optimum configuration, ie horizontal, and thepick-up performance of the cleaner is thereby improved. The location ofthe brush bar in a brush housing which is sealed with respect to thecleaner head body and connected or connectable to a dirty air inlet inthe main body of the housing maintains the freedom of movement of thebrush housing during use but avoids the need to provide flexible sealsbetween the brush housing and the cleaner head body which could becomeworn after an unacceptably short period of time. The connection betweenthe brush housing and the main body of the vacuum cleaner is preferablyformed by a flexible tube or hose which accommodates the relativemovement between the brush housing and the main body without putting theseals under stress.

It is acknowledged that, during the normal forwards and backwardsmovement of the vacuum cleaner, the brush housing may be lifted awayfrom the floor under the influence of the flexible tube or hose. As thisis obviously undesirable a resilient member is preferably providedbetween the brush housing and the cleaner head body to counteract anylifting force acting on the brush housing. The resilient member actsbetween the cleaner head and the brush housing to press the rear of thebrush housing downwardly. The resilient member is preferably a tensionspring.

DETAILED DESCRIPTION OF THE DRAWING

An embodiment of the invention will now be described with reference tothe accompanying drawings, wherein:

FIG. 1 is a side view of a vacuum cleaner incorporating a cleaner headassembly according to the present invention;

FIG. 2 is a side view of the vacuum cleaner of FIG. 1 with the handleshown in an inclined position;

FIG. 3 is a sectional view of the cleaner head of the cleaner of FIGS. 1and 2 in a first position;

FIG. 4 is a sectional view of the cleaner head of the cleaner of FIGS. 1and 2 in a second position; and

FIG. 5 is a sectional view of the cleaner head of the cleaner of FIGS. 1and 2 in a third position.

BRIEF DESCRIPTION OF THE INVENTION

FIGS. 1 and 2 illustrate the overall construction of an upright vacuumcleaner incorporating a cleaner head assembly according to theinvention. The vacuum cleaner 100 has a main body 102 in which dustseparation apparatus 104 is housed. In this embodiment the dustseparation apparatus 104 comprises cyclonic dust separation apparatusconsisting of two cyclones arranged in series. Apparatus of this type iswell known and will not be described any further here because it has nomaterial effect on the invention. A motor housing 106 is located at thelower end of the main body 102 and forms part of the main body 102.Supporting wheels 107 are mounted directly on the side of the motorhousing 106. A cleaner head assembly 108 is rotatably mounted on themotor housing 106 about an axis A. The cleaner head assembly 108 has abrush housing 110 with a downward facing inlet 112 arranged at theforward end of the cleaner head assembly 108. A flexible duct 114extends between the brush housing 110 and a dirty air inlet in the mainbody 102 which communicates with ducting which leads to the dustseparation apparatus 104.

A handle 116 extends upwardly from the lower part of the main body 102and lies alongside the rear part of the main body 102. When the cleaner100 is to be used in the upright mode (as shown in FIG. 1), the handle116 extends upwardly beyond the main body 102 so that it can be grippedby a user and used to manoeuvre the cleaner 100 across a surface to becleaned. The handle 116 is, however, releasable and may alternatively beused as a hose and wand assembly. This can be achieved in several waysand examples are shown and described in EP 0 037 674 and EP 0 134 654.The lower end of the hose/wand 116 is also connected via ducting 118 tothe dirty air inlet of the main body 102 to allow dirt and dust enteringthe cleaner 100 via the hose and wand to be passed to the dustseparation apparatus 104.

A changeover valve (not shown) is provided in order that the appropriateinlet can be automatically selected for different modes of operation.When the cleaner 100 is in the position shown in FIG. 1, the changeovervalve automatically connects the dust separating apparatus 104 to thewand and hose 116 so that cleaner can be used in cylinder mode for abovethe floor cleaning. Air is drawn into the cleaner through the distal end116 a of the wand which can be released from the cleaner for appropriatemanipulation. The inlet 112 in the cleaner head assembly 108 isautomatically shut off. When the cleaner 100 is to be used inconventional upright mode, the handle is restored to the position shownin FIG. 1 and then inclined to the vertical as shown in FIG. 2. Thechangeover valve automatically shuts off the air inlet at the distal end116 a of the wand and connects the dust separating apparatus 104 to theinlet 112 in the cleaner head assembly 108. The construction of thechangeover valve does not form part of the present invention and willnot be described any further here.

In all cases, ie in the upright mode and in the cylinder mode, a motor(not shown) located in the motor casing 106 drives a fan (also notshown) so as to draw air into the cleaner 100 via the appropriate inlet,conduct it to the dust separating apparatus 104 in the main housing 102and then expel the cleaned air to the atmosphere. The cleaned air ispreferably caused to flow past the motor so as to cool it before beingexpelled.

FIGS. 3 to 5 show in more detail the cleaner head assembly 108 formingpart of the vacuum cleaner 100 shown in FIGS. 1 and 2. The cleaner headassembly 108 has a cleaner head body 10 comprising a front portion 12extending laterally across the width of the vacuum cleaner 100 and tworearwardly extending side arms 14 extending rearwardly from the sideportions of the front portion 12. Each side arm 12 has a lug (not shown)which defines an aperture centred on the axis A about which the cleanerhead assembly 108 is pivotably mounted on the motor casing 106. Thecleaner head assembly 108 is mounted on the motor casing by way of pinswhich extend through the apertures in the lugs. The cleaner headassembly 108 pivots freely about the axis A so as to “float” on thefloor to be cleaned without requiring the user to identify and set apredetermined level at which the cleaner head must operate.

The cleaner head assembly 108 includes a brush housing 110. The brushhousing 110 is pivotably mounted on the front portion 12 of the cleanerhead body 10 by way of lugs (not shown) depending from the side portionsof the front portion 12. The brush housing 110 is manufactured from anupper plate 20 and a lower plate 22 which may be made from plasticsmaterial or a metal such as stainless steel. The upper and lower plates20, 22 are joined together by quarter turn fasteners (not shown), bypress-fitting or by other suitable means. A seal 24 is trapped betweenthe upper and lower plates 20, 22 so as to ensure that the seal betweenthe plates 20, 22 is essentially airtight. Rollers 25 are rotatablymounted at the front edge of the lower plate 22 to support the brushhousing 110 on the carpet or other surface to be cleaned. The rollers 25can be positioned at or adjacent the outer edges of the lower surface 22or, alternatively, can either extend continuously or in a spaced manneracross the entire width of the brush housing 110.

A suction opening 112 is formed in the lower plate 22. The suctionopening 112 extends across the entire width of the brush housing 110. Abrush bar 26 is rotatably mounted in the brush housing 110 so that thebristles of the brush bar 26 protrude slightly out of the suctionopening 112. The axis B about which the brush bar 26 rotates iscoincident with the axis about which the brush housing 110 is pivotablymounted on the front portion 12 of the cleaner head body 10. The brushbar 26 is arranged to be drivable by the motor of the vacuum cleaner 100in a conventional manner, for example, by way of a drive belt. The upperplate 20 of the brush housing 110 has a connection opening 28 forconnecting the brush housing 110 to an air inlet 30 on the main body ofthe vacuum cleaner 100. A flexible tube 32 connects the connectionopening 28 with the air inlet 30. The flexible tube 32 is made of anysuitable material, for example, rubber or plastics. From the above, itcan be seen that, in use, the only point of entry for air into the brushhousing 110 is via the suction opening 112 and the only outlet is viathe flexible tube 32 which leads to the main body of the vacuum cleanerand the dust separation apparatus. Dirty air entering the machine doesnot pass through any conduit or ducting arranged inside the cleaner headbody 10 and therefore the need to seal the articulated brush housing 110to the cleaner head body 10 is obviated. Seals can be provided at eachend of the flexible tube 32 to ensure that the connections between thetube 32 and the respective part of the machine is airtight. However,neither seal is required to be flexed or placed under stress duringmovement of the vacuum cleaner when in use. The life of any such sealsis therefore significantly longer than any seals which would be requiredto seal the brush housing 110 to the cleaner head body 10 in a movablemanner.

A hooked projection 34 is provided on the rear of the interior surfaceof the front portion 12 of the cleaner head body 10. The hookedprojection 34 extends forwardly and upwardly as shown in the drawings.An eye projection 36 is also provided on the upper surface of the upperplate 20 of the brush housing 110. The eye projection 36 is locatedforwardly of the hooked projection 34. Both projections 34, 36 arelocated upwardly of the axis B about which the brush housing 100 ispivotably mounted on the cleaner head body 10. A resilient member 38extends between the hooked projection 34 and the eye projection 36. Theresilient member 38 takes the form of a tension spring.

The function of the resilient member 38 is to bias the brush housing 110in an anti-clockwise direction so that the rear portion of the brushhousing 110 is pressed downwardly. The rear portion of the brush housing110 is therefore maintained in contact with the surface to be cleaned.It will also counteract any lifting forces which might otherwise causethe rear portion of the brush housing 110 to be lifted away from thesurface to be cleaned. Because the flexible tube 32 is made from aplastics material, the tube 32 may, under some circumstances, exert someupward lifting forces on the rear portion of the brush housing duringnormal use of the vacuum cleaner 100 and the resilient member 38 isdesigned to counteract these lifting forces.

FIG. 3 shows the relative positions of the motor casino 106, the cleanerhead body 10 and the brush housing 110 when the vacuum cleaner 100 is tobe used in cylinder mode (see FIG. 1). FIG. 4 shows the relativepositions when the handle 116 of the vacuum cleaner 100 is inclined at arelatively small angle to the vertical and FIG. 5 shows the relativepositions when the handle 116 of the vacuum cleaner 100 is inclined at arelatively large angle to the vertical. As the cleaner head 108 is movedbackwards and forwards across the surface to be cleaned, the angle ofinclination of the handle alters. The dual articulation of the brushhousing 110 with respect to the main body 102 of the vacuum cleaner 100(ie, the articulation of the cleaner head 108 about axis A and thearticulation of the brush housing 110 about axis B) means that the brushhousing 110 can remain in a substantially horizontal position at allangles of inclination of the handle 116. This is achieved partly as aresult of the centre of gravity of the brush housing 110 being locatedrearwardly of the axis of articulation B. The weight of the brushhousing 110 urges the rear portion of the brush housing 110 in adownward direction. Any downward force applied to the brush housing 110by the flexible tube 32 will add to the urging of the brush housing 110in the correct direction, as will the action of the resilient member 38.This means that the suction opening 112 will remain in a horizontalplane so as to remain in contact with the surface to be cleaned andmaximum performance of the cleaner head is thus achieved. Maximumperformance of the cleaner head improves the overall vacuum cleanerefficiency. The resilient member 38 also acts to urge the rear portionof the brush housing 110 downwards towards the surface to be cleaned.The rear portion of the brush housing 110 is thus pressed against thefloor.

The invention is not limited to the precise details of the embodimentdisclosed above. Modification not affecting the essence of the inventionare intended to be included within the scope of the invention. Forexample, the tension spring could be replaced by any resilient memberand the seal around the connection point 28 could be formed by anyairtight material. Other modifications and variations will be apparentto a skilled reader.

What is claimed is:
 1. A cleaner head assembly for a vacuum cleaner, thevacuum cleaner comprising a main body having an air inlet forintroducing dirty air thereinto, the cleaner head assembly comprising: acleaner head body pivotably attachable about a first axis to a main bodyof a vacuum cleaner, and a brush housing being a sealed unit pivotablymounted about a second separate axis on the cleaner head body; a suctionopening formed in the brush housing and having a brush bar mounted abouta third axis therein; a conduit, separate from the cleaner head body,connected to the sealed unit and connectable to the air inlet to carrydirty air from the brush housing to the main body.
 2. A cleaner headassembly as claimed in claim 1, wherein the second axis is coincidentwith the third axis.
 3. A cleaner head assembly as claimed in claim 1,wherein the first axis is parallel to the second axis.
 4. A cleaner headassembly as claimed in claim 1, wherein the conduit comprises a flexibletube or hose.
 5. A cleaner head assembly as claimed in claim 1, whereinthe brush housing comprises a front portion and a rear portion, thebrush bar being located in the front portion and the conduit beingconnected to the rear portion.
 6. A cleaner head assembly as claimed inclaim 1, further comprising a resilient member provided between thecleaner head body and the brush housing to bias the brush housing in apredetermined direction of pivoting with respect to the cleaner headbody.
 7. A cleaner head assembly as claimed in claim 6, wherein theresilient member acts so as to urge the rear portion of the brushhousing in a downward direction.
 8. A cleaner head assembly as claimedin claim 6, wherein the resilent member comprises a tension spring.
 9. Avacuum cleaner comprising a main body having an air inlet forintroducing dirty air thereinto, and a cleaner head assembly comprising:a cleaner head body pivotably attached about a first axis to the mainbody; a brush housing being a sealed unit pivotably mounted about asecond axis on the cleaner head body; a suction opening formed in thebrush housing and having a brush bar rotatably mounted about a thirdaxis therein; a conduit, separate from the cleaner head body, connectedto the sealed unit and to the air inlet to carry dirty air from thebrush housing to the main body.
 10. A cleaner head assembly for a vacuumcomprising: a cleaner head body pivotably attachable about a first axisto a main body of a vacuum cleaner; a brush housing pivotably mountedabout a second separate axis on the cleaner head body and having a brushbar mounted therein; said brush housing comprising an upper part, alower part, and a seal located between said upper part and said lowerpart.
 11. A cleaner head assembly as claimed in claim 10, furthercomprising a conduit connected at one end to the brush housing andconnectable at the other end to an air inlet on the main body of thevacuum cleaner.
 12. A cleaner head assembly as claimed in claim 10,wherein the brush bar is mounted about said second axis.
 13. A cleanerhead assembly as claimed in claim 10, wherein the axis of the brush baris located in a front portion of the brush housing.
 14. A cleaner headassembly as claimed in claim 11, wherein the conduit comprises aflexible tube or hose.
 15. A cleaner head assembly as claimed in claim14, wherein the brush housing comprises a front portion and a rearportion, and wherein the brush bar is located in the front portion ofthe brush housing.
 16. A cleaner head assembly as claimed in claim 15,wherein the conduit is connected to the rear portion of the brushhousing.
 17. A cleaner head assembly as claimed in claim 10, wherein thecleaner head assembly further comprises a resilient member providedbetween the cleaner head body and the brush housing to bias the brushhousing in a predetermined direction of pivoting with respect to thecleaner head body.
 18. A cleaner head assembly as claimed in claim 17,wherein the resilient member acts so as to urge the rear portion of thebrush housing in a downward direction.
 19. A cleaner head assembly asclaimed in claim 17, wherein the resilient member comprises a tensionspring.